Welong Supply Chain, is able to manufacture BOHLER S390 wheels with hardness 65~69HRC for drilling tools. BOHLER 5390 MICROCLEAN is produced by powder-metallurgy methods Segregation-free and homogeneous metal powders of highest purity and adequate granulation are processed to homogeneous and segregation-free high speed steels of virtually isotropic properties in a diffusion process taking place at high pressures and temperatures
BOHLER S390 wheels can be hardening. 1150 10 1230°((2102 to 2246° F)
Oil, salt bath (500- 550°C (932 -1022°F), air, gas. Upper temperature range for parts of simple shape, lower for parts of complex shape. For coldworking tools also lower temperature are of importance for higher toughness. Soaking time after heating up the whole section of a workpiece 80 seconds minimum is required for dissolving sufficient carbides. Maximum soaking time 150 seconds to avoid detriments by over soaking.
In practice instead of soaking time the time of exposure from placing the workpiece into the saith bath after preheating until removing (including the stages of heating to the specified surface temperature and of heating to the temperature throughout the whole section) is used. Vacuum hardening is possible. The time in the vacuum furnace depends on the relevant workpiece size and furnace parameters
Then, BOHLER S390 wheels can be tempering. Slow heating to tempering temperature immediately after hardening/time in furnace: 1 hour for every 20mm of workpiece thickness, but not less than 2 hours/ air cooling (minimum holding time: 1 hour). 1st tempering and 2nd tempering to desired working hardness. 3rd tempering for stress relieving, 30~50°C (86~122°F) below highest tempering temperature. Obtainable hardness after tempering 65 – 69 HRC.
Regarding production process of BOHLER S390 wheels: machining (chamfering) + tooth profile machining + heat treatment. Pay special attention to leave a minimum allowance of 0.50mm on one side of the outer diameter during turning for wire cutting to machine the tooth profile.
If you have any requirements or enquiry about Forgings for Cones of drill Bit, please feel free to contact us.
Post time: Sep-19-2023
